A novel photocatalyst with protonated carbon nitride (p-C₃N₄) loaded with IrO₂ quantum dots (QDs) was fabricated via a facile hydrothermal method. Structure characterization studies (XRD, STEM, XPS, UV–vis spectra and PL spectra) revealed that the IrO₂ QDs with an average diameter of ca. 2 nm were highly dispersed and anchored to the surfaces of p-C₃N₄. The introduced IrO₂ QDs promoted the electron–hole separation efficiency of p-C₃N₄ and increased the absorbance capacity within the visible light range. The photocatalytic activity was evaluated using hydrogen and oxygen evolution from water splitting under visible light illumination. The optimum IrO₂/C₃N₄-0.6 wt% photocatalyst exhibits the highest hydrogen evolution rate of 45 μmol h⁻¹ and oxygen production rate of 20 μmol h⁻¹. Under visible light irradiation, the composite photocatalyst shows higher photocurrents, more negative onset potential and lower photoluminescence intensity compared with those of p-C₃N₄, which demonstrated that the modification of IrO₂ QDs accelerated the transformation, separation, and utilization of photoelectrons and thereby significantly improved the photocatalytic performance.

中文翻译：

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质子化的氮化碳纳米片支持IrO ₂量子点，无需牺牲试剂即可进行纯水裂解

通过一种简便的水热法制备了一种新型的负载有IrO ₂量子点（QDs）的质子化氮化碳（pC ₃ N ₄）的光催化剂。结构表征研究（XRD，STEM，XPS，UV-vis光谱和PL光谱）显示，IrO ₂ QD的平均直径约为。2 nm高度分散并固定在pC ₃ N ₄的表面上。引入的IrO ₂量子点提高了pC ₃ N ₄的电子-空穴分离效率并增加了可见光范围内的吸收能力。使用可见光照射下水分解产生的氢和氧来评估光催化活性。最佳的IrO ₂ / C ₃ N ₄ -0.6 wt％光催化剂表现出最高的氢气析出速率为45μmolh ^-1和最大产氧速率为20μmolh ^-1。在可见光照射下，与pC ₃ N ₄相比，复合光催化剂具有更高的光电流，更大的负起始电位和更低的光致发光强度，证明了IrO ₂的改性。 量子点加速了光电子的转化，分离和利用，从而显着提高了光催化性能。